Alabama "Pre-Newbie"

Bert65 · Posted: Sun Jun 07, 2009 9:12 pm Post subject:

Does your omni external antenna have a built in ground plane or is it a magnetic base that is meant to be mounted on a car or truck roof? If it is the magnetic one you may need to supply a ground plane. Here is a link to Jim_in_VA's blog about making a ground plane, lots of other good stuff here also.

http://evdotips.blogspot.com/2008/04/my-antenna-is-crap.html

Seems strange you get no signal improvement when you plug in the omni antenna. Check out the above site for help with a kinds of antennas.

Good luck

colebert · EVDO Junkie Joined: 26 Jan 2007 Posts: 170

Here's what I would do, if I were in your position.

You can obviously tell you're in RevA. However, it could be that although you aren't very far in terms of distance from the tower, you may not have line of sight. Or you could be closer to a non-RevA tower.

First, I would lock my card to EVDO only. Next, I would go for a drive. I would find where all the Verizon towers are. Take your laptop and drive to the tower. Get out of the car and check signal strength. Then run your speed tests. That will give you a baseline to know under perfect conditions what your speeds would be for that tower.

Then, I would get a parabolic grid antenna, a J-mount (like for sat dishes) and some LMR400 cabling. I would also get the correct adapter cable for your EVDO modem. Then I would mount the antenna outside and start tuning it. Point it in the direction of the tower you feel gives you best power/speed. Use your laptop to check signal strength.

I would estimate you would probably need to spend $150-200 for all that. But it's the best money you can spend for a 3G connection that you are going to rely on for primary internet. I have done these installs and they are solid.

It looks like you have 1900MHz EVDO so you would go with this setup.

http://www.l-com.com/item.aspx?id=10041
http://www.l-com.com/item.aspx?id=22739
http://www.l-com.com/item.aspx?id=21603
Ebay item #390053044655
http://www.antennagear.net/servlet/the-605/External-Antenna-Adapter-For/Detail

That should get you started.

kabod · Posted: Tue Jun 09, 2009 7:16 am Post subject:

Thanks everyone for your suggestions...

I can't get the modem to initialize on my HP XP laptop - will take my Dell home from work and try again.

I was ready to order the Grid yesterday but talked to Victor in tech support at the 3G store and he thinks the antenna connection in the modem might be the problem...of course he suggested taking the modem for a ride with the laptop but that didn't work as I stated above.

ChoP, you said you were 10 miles non-LOS but trees would not be my friend... I am only 3 miles but will have to shoot through about 40 acres of pine tree tops (the top 20 feet of 50 foot pines and really only about 1/4 mile straight through) near my house:

Is this a major problem for me? As you can see there is a lot of open fields once I get past the pines. The trees nearer the tower shouldn't be a problem since the tower is at 300 feet...

If the connection in the modem turns out to be the problem and I get it replaced, will the Omni be the better choice at 3 miles? I sure like the gain I see on the parabolic but still don't know enough about all this and need some more input...

colebert - I really like your suggestions and was ready to place the order yesterday until Victor mentioned the possible problem with the modem.
I am half way through my 14 day trial with the 3G store and probable need to send stuff back and start all over again.

colebert · EVDO Junkie Joined: 26 Jan 2007 Posts: 170

That's cool. If you think it might be the modem, you should consider going with a V740 expresscard solution. I have used them with great success. They can be adapted to PCMCIA laptops easily. Plus it fits more securely in a CTR500 than a USB.

One point of caution. I am a 3G store customer and have nothing but praise for their service and committment to 3G-based internet, especially people in your situation. However, one area I have always felt they get low marks from me on is their treatment of parabolic grid antennas. They do not sell them and I have seen them monger fear, uncertainty, and doubt (FUD) concerning them. So keep this in mind when you have exhausted your options with them without having a solid 3G connection. I hope it does not come to that, but remember what I said on this issue. I have deployed many parabolic solutions (after trying expensive Yagis) and have been very happy with the results.

Of course, I ran your path profile and it looking like your LOS is shooting straight through those trees. 1900MHz isn't known for it's ability to go through foliage, especially that much. You do have the fact you are only 3 miles away and everything beyond the trees is a clear shot.

bucrepus · EVDO User Joined: 27 Dec 2007 Posts: 33

Kabod, I live in the Montgomery area north of you. Had kind of the same issue with 4 towers about the same distance from me. I've had the best luck with the UM175 in trying to lock rev A. I had to find the sweet spot for my antenna. Have a lot of RF relections with those multiple towers. Jumped all around between 1X, DO, and RevA. After I found the sweet spot with DO, I updated my PRL from the one the card ships with and get a solid Rev A now. Just had to replace the card Saturday.. It had the same PRL as a year ago, had to update it again to get Rev A from DO (I think I updated it with 51246(8?). If you are using a antenna adapter from the 175 to a Wilson Omni, tone it out with a meter(resistance). I've had more than one of those adapters that was bad... Heck of an aggravation..
Buc

kabod · Posted: Thu Jun 25, 2009 9:51 am Post subject:

OK I'm back....(I've read many a post here that just ended with no follow up as to a resolution...)

Sent my UM175 back and received the new one late yesterday afternoon. Turns out it did have a bad antenna jack.

With the new card and the Wilson Omni I can see an increase from around -92dB to -82dB when I'm out on my roof. I haven't mounted the Omni yet as we had some thunderstorms in the area and I wasn't too keen on standing on a metal roof holding on to a lightning rod!

I was jumping back and forth between National Access and Broadband RevA and even saw some -77dB to -74db a few times. I didn't lock the 175 to RevA during my testing as I was in a hurry to get off of my roof but I did grab this screenshot:

Looks like I may not need a grid antenna but I will do some more testing this afternoon after mounting the Omni higher up....

kabod · Posted: Sat Jun 27, 2009 1:08 pm Post subject:

OK - VERY FRUSTRATED right now!

Spent time this morning on a hot green roof putting up the Omni (which looked promising from the previous post)

Locked in HDR on the modem and IT WOULDN'T EVEN CONNECT! Had to go back to auto to even get a connection....and this is my speed:

This is what I get on National Access at about -92dB...can't see any info on the friggin' CTR500 screen...

The Cradlepoint signal strength stopped working after about 30 minutes with the old UM175 and the folks at 3g thought it was the same issue that kept the antenna connection from working...apparently not.

Since I'm on a 1.9GHz tower I'm not sure about trying to get through these trees-

Should I try a Yagi first???

xrayman · Posted: Sat Jun 27, 2009 3:15 pm Post subject:

ChoP · EVDO User Joined: 13 Jul 2008 Posts: 45 Location: Alabama

An 800 GHz Signal will penetrate foliage better but you have to go with what you got, and if you have a better signal coming from a 1.9 GHz tower then that's the one to use.

The only reason I could think of using a Yagi over a Grid Antenna is to eliminate reflected signals from other towers if they are a problem. The thing about a Grid Antenna is, it doesn't require a "direct line of sight", which in your case would be much more beneficial because you don't have "direct line of sight".

See the problem is an HDR signal may be vertical when leaving the tower but it may not be vertical when you receive it if in a "non-direct line of sight" situation. That signal may bounce around on objects or weave through tree foliage before it gets to you. Heavy foliage will also absorb some of the signal.

The Yagi needs direct line of sight because it will only pick up the vertical signal and the rest is missed. If the signal bounces around and gets a distorted path the Yagi may miss most of it.

The Grid Antenna on the other hand acts as a collector for multi-path signals and will focus them to the dipole of the antenna, making use of the stray signals.

Here you see the Grid Antenna pointed at an Alltel 800 GHz RA cell tower about nine miles away with "non-direct line of sight". Rssi -69 with the amp on. Antenna is only three feet off the ground, sometimes higher is not better. I can move the Dish back ten feet and it will drop the signal to a -88 rssi.

Location is everything!

kabod · Posted: Wed Jul 01, 2009 2:42 pm Post subject:

Thanks ChoP!

WOW! Ten feet back makes that much difference?

I will probably be mounting in the same location as the Omni from my previous shot, as I would have better aiming in case I need to point to a different tower.

I will test the other sites across the bay to see if they are also 1.9Ghz although it might be hard to tell with the ones at 8 miles so close together.
The 2 towers are literally right behind each other from my location.

I praying that the tower 3 miles south will give me a rock solid signal. It is a more rural area and the largest community is a retirement area that has DSL and Cable so I don't think as many would be sucking bandwidth...

ChoP · EVDO User Joined: 13 Jul 2008 Posts: 45 Location: Alabama

Well locking a signal from 9 or 10 miles "non line of sight" is like catching a baseball, the fielder glove has to be in the right spot when the ball comes down.

Diluted22 · EVDO Newbie Joined: 11 Apr 2009 Posts: 1 Location: Alabama

I am still very new to the whole wireless internet, I to live in Alabama and when I received my um150 from Alltel and got it home and hooked it up the best signal I received was 1xRTT 99% signal. Whereas when I purchased the same card for my in-laws (who live only 120 yards away) they were in a constant RA -76 dBm signal with no external antenna ! With this knowledge in hand I starting comparing setups. Low and behold the only difference was the PRL numbers. After a few mins of digging around here on the forums I figured out how to manually update the PRL numbers. Downloaded 5-6 PRL test numbers and within minutes I was in RA coverage. If you haven't tried this I would suggest giving it a whirl.

Jim_in_VA · Posted: Wed Jul 01, 2009 7:49 pm Post subject:

Line of Sight is always better than NLOS. Every foot you raise the antenna you eliminate that more flora between you and the tower. There is a phenomenon known as Fresnel Zone that is too complex to go into this post. Its not so simple as pointing the antenna at a cell tower.
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